HR: 11:05h
AN: T22A-04 [WITHDRAWN] [Abstracts]
TI: Neogene Extension Along The Aegean Forearc Ridge As A Product Of Rapid Slab Roll-Back
AU: * Marsellos, A
EM: marsellos@gmail.com
AF: Earth & Atmos Sci., Univ. at Albany, NY, 12222, 1400 Washington Ave, DEAS 351, ALBANY,
NY 12222, United States
AU: Kidd, W S
EM: wkidd@atmos.albany.edu
AF: Earth & Atmos Sci., Univ. at Albany, NY, 12222, 1400 Washington Ave, DEAS 351, ALBANY,
NY 12222, United States
AB:
Recent detailed mapping and structural observations in Kythera and South Peloponnese demonstrate that there
are ductile, ductile-brittle and some brittle structures in the PQU metamorphic unit and its detachment from cover
sedimentary units that indicate a significant localized NW-SE extension along the Aegean fore-arc ridge (in
contrast to regional extension which is perpendicular to the arc). The youngest brittle structures, which affect
latest Miocene-Pliocene sediments, indicate return to NE-SW regional extension. We recognize this localized
extension of the southwestern part of the Hellenic arc in the Kythera strait as an exceptional arc-parallel extension
of the fore-arc ridge in contrast to adjacent parts of the Aegean arc. Zircon FT cooling ages show exhumation of
the PQU of Kythera at 13 Ma which must correspond to the along-arc extension and the passage through the
brittle-ductile transition. The PQU exhumation structures exposed in Kythera and the nearby area around
Neapolis on the SE Peloponnese contrast with adjacent areas (Peloponnese, and western Crete) where only arc-
perpendicular ductile and brittle structures are developed. We think that the ductile to ductile-brittle extension in
Kythera is related to a tectonic style change of the subduction to rapid slab roll-back/retreat and consequent
expansion and along-strike extension of the fore-arc region, as well as differential rotation (about a vertical axis)
and related bending caused by segmentation and differential forward motion of arc segments.
DE: 8002 Continental neotectonics (8107)
DE: 8107 Continental neotectonics (8002)
DE: 8109 Continental tectonics: extensional (0905)
DE: 8149 Planetary tectonics (5475)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting